#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using namespace atcoder; typedef long long ll; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--) #define repk(i, k, n) for (int i = k; i < (int)(n); i++) #define all(v) v.begin(), v.end() #define mod1 1000000007 #define mod2 998244353 #define mod3 100000007 #define vi vector #define vs vector #define vc vector #define vl vector #define vb vector #define vvi vector> #define vvc vector> #define vvl vector> #define vvb vector> #define vvvi vector>> #define vvvl vector>> #define pii pair #define pil pair #define pli pair #define pll pair #define vpii vector> #define vpll vector> #define vvpii vector>> #define vvpll vector>> // using mint = modint998244353; template void debug(T e) { cerr << e << endl; } template void debug(vector &v) { rep(i, v.size()) { cerr << v[i] << " "; } cerr << endl; } template void debug(vector> &v) { rep(i, v.size()) { rep(j, v[i].size()) { cerr << v[i][j] << " "; } cerr << endl; } } template void debug(vector> &v) { rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; } } template void debug(set &st) { for (auto itr = st.begin(); itr != st.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(multiset &ms) { for (auto itr = ms.begin(); itr != ms.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(map &mp) { for (auto itr = mp.begin(); itr != mp.end(); itr++) { cerr << itr->first << " " << itr->second << endl; } } void debug_out() { cerr << endl; } template void debug_out(Head H, Tail... T) { cerr << H << " "; debug_out(T...); } using mint = modint998244353; void debug_mint1(vector &vec) { for (int i = 0; i < vec.size(); i++) { cerr << vec[i].val() << " "; } cerr << endl; } void debug_mint2(vector> &vec) { for (int i = 0; i < vec.size(); i++) { for (int j = 0; j < vec[i].size(); j++) { cerr << vec[i][j].val() << " "; } cerr << endl; } } int main() { ll D, Q; cin >> D >> Q; vector A(Q); vector B(Q); ll INF = 2000000000000000023; set> st; st.insert(make_pair(-INF, -INF)); st.insert(make_pair(INF, INF)); ll ans = 0; for (ll i = 0; i < Q; i++) { cin >> A[i] >> B[i]; ll min_val = A[i]; ll max_val = B[i] + 1; auto itr = st.lower_bound(make_pair(A[i], B[i] + 1)); itr--; if ((*itr).second >= A[i]) { min_val = min(min_val, (*itr).first); st.erase(itr); } ll lower = A[i]; while (true) { auto it2 = st.lower_bound(make_pair(lower, lower)); // debug_out((*it2).first, (*it2).second); if ((*it2).first > B[i] + 1) { break; } max_val = max(max_val, (*it2).second); st.erase(it2); } ans = max(ans, max_val - min_val); st.insert(make_pair(min_val, max_val)); cout << ans << endl; } }